Respond to all questions clearly giving explanations to your workings.

(1) Discuss the suitability of the crude death rate, the standardised mortality rate and the standardised mortality ratio for comparing: (a) the mortality, at different times, of the population of a given country (b) the mortality, at a certain time, of two different occupational groups in the same population [6] (ii) The following table gives a summary of mortality for one of the occupational groups and for the country as a whole. Occupation A Whole country Age group Exposed to Deaths Exposed to Deaths risk risk 20-34 15,000 52 960,000 3,100 35-49 12,000 74 1,400.000 7,500 50-64 10,000 109 740,000 7,100 Total 37,000 235 3,100,000 17,700 Calculate the crude death rate, the standardised mortality rate and the standardised mortality ratio for Occupation A. [4]In any year, the rate of interest on funds invested with a particular company has mean value / and standard deviation s, and is independent of the rates of interest in all previous years. (i) Derive formulae for the mean and the variance of the accumulated value after n years of a single investment of 1 at time 0. [5] (ii) Let i, be the rate of interest earned in the rth year. Each year the value of (1 + i, ) is lognormally distributed, with parameters / = 0.04 and o- = 0.09. (a) Show that ", the number of years that must elapse before the accumulation of a lump sum invested at time 0 has a 75% probability of at least doubling in size, satisfies: 0.04n -0.2024vm - In 2 =0 (b ) Hence, or otherwise, calculate the value of n. [8] [Total 13](a) () Define the term "economic integration". (2 marks) (ii) Discuss factors which are favourable for economic integration. (6 marks) (b) Discuss the advantages of regional economic integration among African countries. (12 marks) (Total: 20 marks)